CSVDataStore has been improved with write access and the ability to work with different kinds of CSV files (including lat/lon and WKT). Thanks to Travis Brundage for this work.

AbstractDataStore is now deprecated. Please make plans to migrate to ContentDataStore. There is an extensive ContentDataStore tutorial to help with your migration.

PropertyDataStore
has now been ported to use ContentDataStore, and a wide range of
issues (readers, events, transactions) have been resolved for all DataStore implementations. Thanks to Torben Barsballe for this
extensive QA work.

CSS Module

The gt-css module is a brand-new implementation of CSS-style support, now written in Java. Thanks to Andrea Aime for bringing this exciting approach to styling within easy reach of Java developers. Here is a quick code example: